A cooling fan is an important element in a computer heat dissipating system. A reliable cooling fan with extended service life ensures stable operation of a computer system. Among others, the bearing of the cooling fan is particularly important to extend the fan life and reduce the noise produced during fan operation.
Motor bearings for cooling fan may be generally divided into two major types, namely, ball bearings and self-lubricating bearings. In considering of the manufacturing cost, the self-lubricating bearing producing low noise and having low price is more frequently adopted in the cooling fan.
However, when the cooling fan operates, particularly in a high-temperature wording environment, lubricating oil in the be a ring will move along the fan shaft due to adsorption and centrifugal effects, and is thrown to a fan housing of the cooling fan via blades thereof.
When the lubricating oil keeps seeping out of the bearing and being centrifugally thrown out over a long period of time, the lubricating oil in the bearing is largely reduced to cause half-dry friction, or even dry friction between the bearing and the shaft of the cooling fan, which produces abnormal sound, vibration, and loud noise, when the fan operates.
Therefore, it is, tried by the inventor to develop an oil storage means that provides good oil-sealing performance to improve the lubricating condition, and accordingly, the service life of the self-lubricating bearings.